Roadbed joint seal

ABSTRACT

An elastomer joint seal for modular, slab-like construction elements such as pavements, roads, walls and the like. The seal is an elongated parallel-piped and is placed between facing edges of adjacent modular elements. Crossed spring elements run longitudinally of the seal and define an X-configuration in cross-section. Upon movement of the modular sections relative to each other, the spring elements undergo deformation in their respective planes.

[ Oct. 23, 1973 United States, Patent Pare [ ROADBED JOINT SEAL [76]Inventor: Robert Lee Pare, 27 Chiswick Rd., Primary Examiner Mari"Parsons Edgewood Rl 02903 Attorney-Thomas J. Greer, .lr.

June 26, 1972 [21] Appl. No.: 266,471

ABSTRACT [22] Filed:

An elastomer joint seal for modular, slab-like construction elementssuch as pavements, roads, walls and [52] US. Cl. 4114/67 h lik h sea] isan elongated para]]e| piped and is Int. la ed between facing edges ofadjacent modular ele- [58] Field of Search..........................404/67, 66, 44

ments. Crossed spring elements run longitudinally of the seal and definean X-configuration in crosssection. Upon movement of the modularsections relative to each other, the spring elements undergo deformationin their respective planes.

[56] References Cited UNITED STATES PATENTS 8 Claims, 5 Drawing FiguresROADBED JOINT SEAL This invention relates to a seal for use in jointsfor pavements, roadbeds, wall panels, and the like, wherein thepavement, road or structural panel is composed of a plurality of modularsections or units each subject to expansion and contraction asoccasioned by changes in ambient temperature or moisture. It is animprovement on my prior U.S. Pat. No. 3,504,597.

In the construction of a pavement or roadbed, the'top surface is definedby a plurality of aligned and generally rectangular concrete slabs,either formed in situ or prefabricated, placed on a base or substrate.Spaces are left between the aligned slabs to allow for individualexpansion and contraction of the slabs due to ambient temperaturevariations. Thus, the resultant pavementor roadbed is defined by asubstrate or base upon which are placed a plurality of generallyrectangular slabs, with gaps between the slabs running generallytransverse to the longitudinal axis of the pavement or roadbed. It willbe apparent that the gaps are entirely necessary in the case ofexpansion of the slabs, otherwise, buckling or fracture of theindividual slabs would accompany temperature increases and failure ofthe slabs in tension would accompany temperature decreases.

This art has long been aware of various sealing elements between suchmodular units. Here, the worker in this art is referred to the followingUnited States patents as exemplary of sealing elements between pavementsof roadbed sections U.S. Pat. Nos. 3,324,775; 3,276,336; 3,179,026;3,479,933; 2,315,588 and 2,071,299. In the latter three patents anelastomeric element, such as rubber, is provided with an internal cavityand a sheet metal spring element placed within the cavity. The functionof the internal spring element is to produce forces laterally of the gapbetween the slabs, i.e., in a direction parallel to the longitudinalaxis of the roadbed, for the purpose of taking up increases in the widthof the gap which would accompany contraction of the individual modularunits. The deformation of the seal which is defined by the elastomer andthe spring element further accomodates a narrowing of the gap uponexpansion of the individual modular elements. In the first threementioned United States patents, an internal spring element is absentand the required resiliency of the sealing member is provided by theproperties'of the elastomer member itself. Thus, deformation of thesealing element is made possible by cavities therein. While prior artstructures such as those above listed have probably been at leastpartially satisfactory, certain disadvantages have been observed such asthe formation of a depression or of a bulge in the top portion which issubstantially coplanar with the pavement or roadbed surface. In the caseof a seal entirely formed of an elastomer, the struts are folded inwardon one another causing severe bending in the walls in the compressedposition, thus developing compression set and reduction in recovery tothe expanded position. Continued exposure of the seal to the atmospherefurther inhibits the ability of the seal to expand during periods of lowtemperatures.

In my prior U.S. Pat. No. 3,504,597 it has been found that the single,planar internal spring does not always remain in a vertical plane upondeformation, rather its top or bottom edges undergo excursionstherefrom.

According to the practice of the present invention, a joint which sealsthe gap between adjacent modular sections in a roadbed, pavement, orstatic building structure, is provided which employs a generally tubularelastomer member in combination with internal spring elements. Springelements having substantially well defined planes are inserted withinthe elastomer seal. The planes of the springs are crossed, thelongitudinal edges of any one spring bearing against diagonally oppositelongitudinal edges of the elastomer tube (parallelpiped).

IN THE DRAWINGS:

FIG. 1 is a perspective and partially broken view of the joint seal ofthis invention according to a first embodiment;

FIG. 2 is a cross-sectional view, looking longitudinally of the joint,of the joint shown in FIG. 1;

FIG. 3 is a view taken along line 33 of FIG. 2;

FIG. 4 is a view similar to FIG. 2 andillustrating a second embodimentof the invention;

FIG. 5 is a view similar to FIG..2 and illustrating another embodiment.

Turning now to FIG. 1 of the drawings, the numerals l0 and 12 denoteadjacent and facing modular roadbed sections of concrete or the like.Each section is formed with a ledge 14 such as illustrated on thesection 10 and each with a top load-bearing portion 16 and 18. It willbe understood that the surfaces 16 and 18 constitute adjacent surfaceswhich may either define a primary load bearing surface or may be coveredwith a suitable cover or secondary layer such as asphalt.

The numeral 20 denotes generally an elastomer seal according to thisinvention and is in the form of an elongated and hollow element havingtwo generally opposite' and parallel facing sides, each of which issubstantially planar, and having a top portion which is generallyplanar. The seal 20 extends completely across the gap between theadjacent modular sections 10 and 12, the gap being denoted by thenumeral 22 in FIG. 2.

The seal 20 comprises generally opposite and planar facing walls 24 and26 which abut modular concrete sections 12 and 10. The top of theelongated seal 20 is generally planar and comprises a cap or top 28centrally interrupted by a depression 30. Integral webs 32 and 34 jointop 28 and side walls 24 and 26 as best indicated at FIG. 2. A bottomclosure 38 is defined by two integral webs at the bottom edges of theside walls.

Two planar springs 40 and 42, of identical construction, cross eachother to define a generally X- configuration in transversecross-section. Each spring is formed of metal wire and has a series oftwo loops. The loops are longitudinally spaced along runner portion 43,the latter continuously bearing against one interior corner of the seal20 while the spaced outermost loops engage the diagonally oppositeinterior corner. The springs may be placed inside the elastomer tube sothat they are in compression in their respective planes, the compressionand attendant force urging diagonally opposite corners of the tube awayfrom each other. In other intended uses the springs may not undergodeformation until insertion of the seal into the gap.

It will be clear that as the modular roadbed sections move towards andaway from each other the force of the springs 40 and 42 will compel theside walls 24 and 26 to follow such excursions, thus always maintainingan effective seal across gap'22. Each of the springs 40,42 being incompression in its own plane, the walls 24 and 26 are under verticaltension, thus maintaining the walls flat against the sides of theroadbed gap.

In FIG. 4 an embodiment is illustrated in which upper and lower portionsof the seal are of elastomer, as in the previously described embodiment,but in which the side walls are fashioned either of metal or plastic.The numerals 55 and 57 denote the side walls and are swaged over at bothlongitudinal edges to retain springs 40 and 42 by virtue of theresultant longitudinal channel. The lower elastomer portion or cap isdenoted by the numeral 380 and includes integral webs 50 and rectangularsaw-tooth sides 52 which engage the facing walls of gap 22.

A third embodiment is illustrated at FIG. 5 in which the upper elastomermember 60 includes integral webs 62 and side skirts 520 also havingrectangular sawtooth elements to engage the gap walls. Again, the sidewalls 550 and 570 are of metal or plastic and are swaged along theirlower longitudinal edges to retain the springs. The latter are envelopedin a polyetholene sheath or film 64 to preclude degradation byoxidation. The upper longitudinal edges of the side walls are jointed tothe interior edges of the side skirts 520 by a suitable adhesvie. Thelower portion of the seal is open, having no distinct closure analagousto portions 38 and 380.

I claim:

1. A seal adapted to be placed between facing edges of adjacent modularunits, such as roadbed slabs, said seal including,

a. a pair of parallel and longitudinal side walls spaced from eachother,

b. a pair of springs of the same longitudinal extent as said side walls,each of said springs lying in a plane, said planes intersecting eachother,

c. each of said springs having a loci of points defining twolongitudinal edges therefor,

d. the longitudinal edges of the springs positioned at, respectively,opposite diagonal longitudinal edges of said side wall, to thereby urgethe side walls apart when the springs are under compression,

e. an elastomer top cap extending across the top longitudinal edges ofsaid side walls.

2. The seal of claim 1 wherein said elastomer cap and side walls areintegral.

3. The seal of claim 2 wherein the bottom longitudinal edges of saidside walls are provided with integral extensions which are joined toform a bottom closure.

4. The seal of claim 1 including a bottom cap, said bottom cap being thesame construction as the top cap and fixed to the lower longitudinalside walls in the same manner as the top cap.

5. The seal of claim 1 wherein said springs are encased in a plasticsheath.

6. The seal of claim 1 wherein said springs are each of wire and includelongitudinally spaced loops extending from a main runner portion.

7. The seal of claim 4 wherein the upper and lower longitudinal edges ofsaid side walls are of a rigid material and are inwardly swaged, towardeach other, to define longitudinal channels for the reception of saidsprings.

8. The seal of claim 1 wherein the said side walls are of a rigidmaterial.

1. A seal adapted to be placed between facing edges of adjacent modular units, such as roadbed slabs, said seal including, a. a pair of parallel and longitudinal side walls spaced from each other, b. a pair of springs of the same longitudinal extent as said side walls, each of said springs lying in a plane, said planes intersecting each other, c. each of said springs having a loci of points defining two longitudinal edges therefor, d. the longitudinal edges of the springs positioned at, respectively, opposite diagonal longitudinal edges of said side walls, to thereby urge the side walls apart when the springs are under compression, e. an elastomer top cap extending across the top longitudinal edges of said side walls.
 2. The seal of claim 1 wherein said elastomer cap and side walls are integral.
 3. The seal of claim 2 wherein the bottom longitudinal edges of said side walls are provided with integral extensions which are joined to form a bottom closure.
 4. The seal of claim 1 including a bottom cap, said bottom cap being the same construction as the top cap and fixed to the lower longitudinal side walls in the same manner as the top cap.
 5. The seal of claim 1 wherein said springs are encased in a plastic sheath.
 6. The seal of claim 1 wherein said springs are each of wire and include longitudinally spaced loops extending from a main runner portion.
 7. The seal of claim 4 wherein the upper and lower longitudinal edges of said side walls are of a rigid material and are inwardly swaged, toward each other, to define longitudinal channels for the reception of said springs.
 8. The seal of claim 1 wherein the said side walls are of a rigid material. 